Thank you for having such a wonderful source of information on here. I just started making cheese and want to start doing some aging so need a cave. To complicate things, I will be moving to New Zealand in about 3 months, so would like to plan ahead.

My question is, do you think this is the best plan for my situation? Also, I have absolutely no "wiring skills", so when they talk about re-wiring the thermostat, is this something that anyone can do, how long does this process take (15min? 3 hrs?) and do I need any special tools to do that?

If you use a step down transformer and plug your thermostat into it then no rewiring is required. the step down transformer is like the outlet on your wall in the US.

If you want to plug the thermostat directly into 220v its circuit determines the changes needed from none othe than a plug adapter to minor internal surgery. Can't tell you what to do without a schematic. Probably not worth the effort since a transformer solve the problem handily.

Some thermo/hygro stats on ebay works on wide range of voltage like this one I bought. It works with 85v to 265v so it is quite compatible wherever you go on the surface of the earth. No re-wiring required.